My dad doesn't let us let the dog make on the lawn because he says the grass will turn yellow. Is that true?

Yes it is true sometime you do see big yellow splotches from it. Females are worse than males perhaps because they to just go in one spot. I think some females are worse than others too. You can buy products to help the grass recover.

While dogs prefer grass, they can be trained to use pavement or pea gravel.